Signal-transmitter.



B. F. MERRITT.

SIGNAL TRANSMITTER.

APPLICATION FILED JUNE 30,1915.

' Patentied Mar. 13, 1917.

lnven/or Benjamin F Mel H77 y A ffy Wi/n esses:

UNITED STATES PATENT OFFICE.

BENJAMIN FREDERIC MERRITT, OF EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, TO WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Mar. 13, 1917.

Application filed June 30, 1915. Serial N 0. 37,236.

To all whom it may concern:

Be it known that I, BENJAMIN FREDERIO MERRITT, a citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Signal-Transmitters, of which the following is a full, clear, concise, and exact description.

This invention relates to signal transmitters of the automatic type, and its principal object is to provide a transmitter wherein the signal impulse combinations may be reliably separated and interrupted without necessitating an excessive inactive portion of the signal wheel, and which is of an exceedingly simple and reliable construction.

In the signal transmitters of the general type now used in night watch and fire alarm systems, it is the custom to control the cooperation between the code signal wheel and the circuit controlling springs by means of a cam on the .main driving shaft. This shaft rotates slowly in comparison to the signal wheel, and because of the gradually elevating cam construction required, the withdrawal of the circuit controller from the signal wheel takes place so slowly that an excessive portion of the signal wheels circumferential surface must be sacrificed in order to insure the proper termination and non-interference of signals. It is also necessary to overcrowd the impulse controlling teeth on the wheels in order to allow sufficient vacant space for the operation of the circuit controller removing mechanism.

For the accomplishment of the above objects and the elimination of the above objections, the invention contemplates a. transmitter wherein the cooperation of the signal wheel and circuit controller is effected by mechanism under the conjoint control of the power system and a member rotating with the relatively rapidly moving signal wheel. The cooperation of the various elements is such that the above mechanism also controls the starting and stopping of the transmitter.

The above and other objects of this invention will be fully set forth in the following description and claims, and will be more readily understood by reference to the accompanying drawing, wherein the preferred construction of the transmitter is shown in perspective.

Signal transmitters of this general type are provided with one or more signal wheels 10, on whose circumferential surfaces are groups of projecting teeth arranged in various combinations to control the formation of the code signal impulses. These wheels are mounted on and rotated in the direction of the arrow by a shaft 11 which is provided with suitable bearings in the transmitter framework. Shaft 11 is provided with a pinion 12 engaging a gear wheel 13, whose associated driving pinion 14 engages a gear wheel 15. Gear wheel 15 is loosely mounted upon a shaft 20 which carries a ratchet wheel 21. A spring tensioned pawl 22 carried by gear wheel 15 is adapted to engage the teeth of ratchet wheel 21 so that the rotation of-shaft 20 in one direction carries with it gear wheel 15, while its rotation in the other direction is made free by the slipping of pawl 22 over the teeth of ratchet wheel 21. A spring 25 has one end secured to shaft 20 while its other end is secured to the transmitter framework. This spring may be wound by the rotation of shaft 20 in the direction of the arrow by a, suitable hand operable lever 26.

In operating the transmitter, lever 26 is moved to the left until it strikes a suitable stop (not shown), and is then released. This movement of lever 26 has no eflect upon the train of gears connected to gear wheel 15 because of the fact that pawl 22 slips inoperatively over the teeth of ratchet wheel 21. Spring 25, however, is put under tension by this operation. The release of lever 26 allows spring 25 to rotate the gear train and signal wheels 10 in the direction of the arrow under the control of an escapementsystem comprising a gear wheel 30 carried by shaft 11, a pinion 31 engaging gear wheel 30 and carrying an escapement wheel '32, whose teeth cooperate with a suitable anchor 33.

The circuit controller, which comprises one or more contact springs 35, is insulatively carried by a lateral extension of a member 36 which is pivoted to the framework at 34, and under the tension of a spring 37 Member 36 has an extension 38 cooperating with a cam 39 carried and rotated by shaft 20 of the power system. Member 36 is also provided with an extension 40 cooperating with a stop 41 which is in the form of a cam carried and rotated by shaft 11.

The transmitter is shown in its normal or inoperative condition with extension 38 resting in a depression 42 of cam 39, and extension 40 resting against an end surface 43 of a depression 44 of stop 41. End surface 45 of depression 44 is substantially perpendicular to the circumferential surface of stop 41 so that when the time arrives for spring 37 to move member 36, as will be presently explained, this movement may take place suddenly. The rotation of lever 26 to the left, as previously described, to tension spring 25, rotates cam 39, and extension 38 of member 36 rides out over an inclined surface 50 of the cam upon the camselevated surface. This movement rotates member 36 about its pivot 34 against the force of spring 37 depresses the circuit controller into cooperative relation with the signal wheels, and raises extension 40 out of the depression 44 of stop 41. When the extreme position of lever 26 is reached, extension 38 is resting upon the circumferential surface of cam 39 a considerable distance in advance of this cams depression 42 so that circuit controller 35 and extension 40 are respec tively held in their depressed and elevated conditions. Upon the release of lever 26, the power system rotates I cam 39 and signal wheels 10, the teeth on the latter cooperating with circuit controller 35 to effect the production of a desired code signal. At the beginning of this rotation shaft 11 carries the depressed portion 44 of stop 41 beyond the range of extension 40, and shaft 11 must make at least one approximately complete rotation before extension 40 can be again forced into depression 44 by spring 37. Moreover, because of the additional necessary coperation of extension 38 and depression 42 of cam 39, cam 39 must be returned a suflicient amount to bring extension 38 above depression 42 before extension 40 can be moved into depression 44.

As the end of the train of signals approaches, cam 39, moving in the direction of the arrow, reaches a position where its depressed portion is presented before extension 38. The depression in stop 41, however, is so positioned that it is not at this time presented before extension 40. When, however, the time for interrupting the cooperation of circuit controller 35 and signal wheels 10 is reached, the depressed portion of stop 41 comes before extension 40, and member 36 together with its extensions are rotated in an anti-clockwise direction by spring 37. This rotation of member 36 removes controller 35 from cooperative relation with signal wheels 10 and places extension 40 in a position to be subsequently engaged by surface 43 of the depression in stop 41. Because of the comparatively rapid movement of shaft 11 and the abrupt drop offered by the perpendicular surface 45, this movement of member 36 may take place very quickly, and an undue amount of the circumferential surface of the signal wheels need not be left blank to give a sufliciently long period of time for the retraction of the circuit controller. After extensions 38 and 40 have been forced into the depressions 42 and 44 respectively, the power system continues to rotate shafts 20 and 11 until extension 40 engages the surface 43 of stop 41, whereupon the transmitter is brought to rest in the normal condition shown.

The number of rotations of the signal wheels may be varied by the movement of lever 26 and the position of the depressed portion of cam 39, but the point in a revolution where the controller will be removed from the signal wheels, and the signal wheels and the power system will be brought to rest, is determined by extension 40 and the end surfaces of the depression in stop 41.

The invention claimed is:

1. A signal transmitter comprising a signal wheel, a circuit controller adapted to cooperate therewith, a power system for rotating said wheel, a stop rotating with said wheel and mounted on the same shaft, and a member controlled conjointly by said system and said stop and cooperating with said controller for allowing and arresting the rotation of said wheel and effecting and terminating the. cooperation between said wheel and said controller.

2. A signal transmitter comprising a signal wheel, a cam rotating therewith, a circuit controller adapted to cooperate with said wheel, means for rotating said wheel, and a member supporting said controller and cooperating with said cam and said means for releasing said wheel and bringing said controller into operative relation with said wheel.

3. A signal transmitter comprising a signal wheel, a cam rotating therewith, a circuit controller ada ted to cooperate with said wheel, means or rotating said wheel,

and a member supporting said controller and controlled by said cam and said means for arresting the rotation of said wheel and removingsaid controller from operative relation with said wheel.

4. A signal transmitter comprising a signal wheel, a circuit controller adapted to be,

engaged thereby, a power system for rotating said wheel, a member cooperating with 5 said system and controlling the relation between said wheel and said controller, and means associated with said wheel and acting on one end of said member to arrest the rota tion of said wheel and terminate the engagement between said wheel and said controller. 10

In witness whereof, I hereunto subscribe my name this 29th day of J une, A. D. 1915.

BENJAMIN FREDERIG MERRIT'I'. 

